Objective:Surgical site infection (SSI) is a common health care-related infection after gastrointestinal surgery. Once SSI occurs after surgery, it can significantly prolong the postoperative hospital stay, increase the cost burden of patients and society, and even endanger the life safety of patients. The purpose of this study was to investigate the clinical phenotypes of gastrointestinal surgery, identify the clinical characteristics of SSI, and provide reference for the prevention of SSI after gastrointestinal surgery.Methods:This is a multicenter prospective cohort study that collected clinical data from all adult patients undergoing gastrointestinal surgery from March 2021 to February 2022 at 42 hospitals in China, including baseline and perioperative characteristics. Based on the variables associated with SSI, latent class analysis (LCA) was used to explore the population characteristics of SSI.Results:In total, 16 087 patients were included in the study, of whom 345 (2.1%) developed SSI. LCA analysis revealed that patients undergoing gastrointestinal surgery were classified into four clinical phenotypes, including α (3851), β (1538), γ (6387), and δ (4311). Type α had minimal abnormality on related system functions (ASA score > 2: 4.5% [173/3851]), and mainly underwent appendix surgery (98.9% [3808/3851]). The postoperative SSI incidence of type α was 0.4% (16/3,851), which belonged to the group of SSI low risk. The abnormality of system functions of type β (ASA score > 2: 17.4% [268/1538]) was worse than that of type α. Type β mainly underwent stomach surgery (72.4% [1113/1538]), and its incidence of postoperative SSI was 1.2% (18/1538), belonging to the group of SSI medium risk. The ASA score of type γ (ASA score > 2: 18.0% [1148/6387]) was comparable to that of type β. Type γ mainly received colorectal surgery (colon surgery: 40.1% [2562/6387]; rectal surgery: 33.6%[2143/6387]), and its incidence of postoperative SSI was 1.7% (106/6387), belonging to the group of SSI medium risk. Type δ (ASA score > 2: 23.5%[1015/4311]) was the most serious type with the highest proportion of open surgery. Type δ mainly underwent small intestine (54.0%[2327/4311]) and stomach surgery (32.3% [1392/4311]) and had the highest incidence of SSI (4.8% [205/4311]) and the highest mortality rate (0.6% [24/4311]), belonging to the group of SSI high risk. Compared with type α and β, the median length of hospital stay (α, β, γ, and δ: 5.0 days, 9.6 days, 13.0 days, and 16.0 days, P<0.001) and postoperative hospital stay (α, β, γ, and δ: 4.0days, 6.0days, 8.3 days, and 10.0 days, P<0.001) of type γ and δ were significantly increased, and the median medical costs (α, β, γ, and δ: 14 178.7 yuan, 39 514.2 yuan, 62 893.0 yuan and 57 266.6 yuan, P<0.001) were also significantly increased. Conclusion:LCA analysis elucidated four clinical phenotypes of patients undergoing gastrointestinal surgery. Type α had a low risk of SSI. Type β and γ had a medium risk of SSI, and type δ had a high risk of SSI.

Objective To independently design a protective restraint band used for the interventional catheter bed and to evaluate its application effect.Methods The self-designed restraint belt consisted of a restraint belt body,first movable band and second movable band.A total of 200 patients,who received interventional operation at the Affiliated Run Run Shaw Hospital,School of Medicine of Zhejiang University of China from October 2022 to March 2023,were collected for this study.The patients were divided into the study group(n=100,using the self-designed restraint belt)and the control group(n=100,not using the self-designed restraint belt).The duration of surgical interruption due to patient's factors and the incidence of restraint belt-related adverse events were compared between the two groups.Results The duration of surgical interruption of the study group was(0.26±0.12)min,which was significantly shorter than(1.46±0.50)min in the control group,the difference was statistically significant(t=-23.570,P＜0.01).The incidence of restraint belt-related adverse events in the study group and the control group was 0％and 7％respectively,the difference was statistically significant(x2=6.380,P=0.012).Conclusion The protective restraint band used for the interventional catheter bed can reduce the incidence of restraint belt-related adverse events and improve surgical efficiency.

Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53％,out of which 304 CRE strains were detected through routine detection(detection rate 3.90％),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87％).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31％.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P＜0.001).In the study group,CRE detection rate of active screening(11.87％)was higher than that of routine detection(3.90％),with statistically significant difference(x2=264.26,P＜0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92％vs 73.41％)and Serratia marcescens(2.30％vs0.23％)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22％vs 19.55％),all with statistically significant differences(all P＜0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.

Objective:To explore the characteristics of brain structure and morphology changes in patients with chronic knee osteoarthritis(OA).Method:Voxel-based morphometry(VBM)analysis,surface-based morphometry(SBM)analysis and structural covariance networks(SCN)based on gray matter volume were used to exam the differences in brain structure and morphology between patients with chronic knee osteoarthritis(KO A)and healthy control(HC).Result:①VBM analysis:Compared with HC subjects,chronic KOA patients showed a significant reduction in gray matter volume of the left temporal pole as the central region(voxels level,P＜0.001;cluster level,P=0.049,FWE correction,voxels size=833).②SBM analysis:Compared with HC subjects,the sulcus depth in the pars opercularis of the left inferior frontal gyrus decreased significantly in patients with chronic KOA(voxels level,P＜0.001;cluster level,P=0.003,FWE correction,voxels size=293).③SCN analysis:Compared with HC subjects,the SCN constructed based on local gray matter volume in patients with chronic KOA was more robust than that in healthy controls(P=0.032).Conclusion:Chronic KOA patients have structural abnormalities in the brain,providing a new insights into the potential impact of chronic KOA on the central nervous system.

Objective:To establish a normal data model of fetal right ventricular size and function using echocardiography，and to explore the clinical value of quantitative assessment of right ventricular size and function in the diagnosis of congenital heart diseases.Methods:（1）A simple random sampling method was employed to collect 1 004 pregnant women with normal singleton pregnancies at 24 to 32 +6 weeks of gestation who underwent fetal cardiac ultrasound examinations at the First Affiliated Hospital of Air Force Medical University from January 2021 to December 2023. Two-dimensional and M-mode echocardiography were used to measure the right ventricular end-diastolic diameter（RVEDD），right ventricular end-diastolic area（RVEDA），tricuspid annular plane systolic excursion（TAPSE）during systole，and the right ventricular fractional area change（RVFAC）was calculated. The correlations between the above parameters and ultrasound gestational age（USGA）were analyzed. Moreover，percentile growth curves for each parameter were plotted. With the above parameters as dependent variables and the USGA as the independent variable，a Z-score model was established through regression analysis.（2）A stratified sampling method was adopted to select 30 fetuses diagnosed with hypoplastic right heart syndrome（HRHS）and 30 fetuses diagnosed with pulmonary stenosis（PS）during the same period as the case group. The model was verified，and the morphological and functional characteristics of the right ventricle were analyzed. Results:The data of RVEDD，RVEDA，TAPSE，and RVFAC in normal fetuses showed a skewed distribution. Each parameter showed good linear correlations with USGA（ r=0.836，0.834，0.846，0.242；all P<0.001）. The constructed percentile curves for each parameter indicated that RVEDD，RVEDA and TAPSE increased significantly with the growth of USGA，while RVFAC showed a slow downward trend. All parameters in the HRHS group and TAPSE and RVFAC in the PS group deviated significantly from the normal reference range（all P<0.001）. Conclusions:By analyzing RVEDD，RVEDA，TAPSE and RVFAC of normal fetuses，the percentile and Z-score normal reference value models of multiple parameters of fetal right ventricular size and function have been established，providing corresponding standards for quantitative analysis.

Objective:To explore the characteristics of brain structure and morphology changes in patients with chronic knee osteoarthritis(OA).Method:Voxel-based morphometry(VBM)analysis,surface-based morphometry(SBM)analysis and structural covariance networks(SCN)based on gray matter volume were used to exam the differences in brain structure and morphology between patients with chronic knee osteoarthritis(KO A)and healthy control(HC).Result:①VBM analysis:Compared with HC subjects,chronic KOA patients showed a significant reduction in gray matter volume of the left temporal pole as the central region(voxels level,P＜0.001;cluster level,P=0.049,FWE correction,voxels size=833).②SBM analysis:Compared with HC subjects,the sulcus depth in the pars opercularis of the left inferior frontal gyrus decreased significantly in patients with chronic KOA(voxels level,P＜0.001;cluster level,P=0.003,FWE correction,voxels size=293).③SCN analysis:Compared with HC subjects,the SCN constructed based on local gray matter volume in patients with chronic KOA was more robust than that in healthy controls(P=0.032).Conclusion:Chronic KOA patients have structural abnormalities in the brain,providing a new insights into the potential impact of chronic KOA on the central nervous system.

Objective:To explore the psychological experience of ICU nurses caring for young patients with suicide attempts in a general hospital, and to lay a foundation for the study of psychological adjustment and intervention for ICU nurses.Methods:Twelve ICU nurses who had experience of caring for suicide attempted- young patients from Sir Run Run Shaw Hospital Affiliated to Medical College of Zhejiang University were selected by using descriptive qualitative research method and the maximum difference method of the purposive sampling during October to December in 2023, and semi-structured in-depth personal interviews were conducted. Traditional content analysis method was used to sort out and analyze the data and extract the themes.Results:A total of 12 nurses completed the interview, 5 males, 7 females, aged 23-38(29.33 ± 4.14) years, three themes and seven sub-themes were extracted: psychological characteristics of care (avoidance of active communication, fear of care, empathy); the support required for nursing care (support from colleagues; support from nursing managers); self-growth after caregiving (self-growth in terms of life and death, and self-growth in terms of children′s education).Conclusions:ICU nurses have a certain degree of psychological pressure when taking care of young patients with suicide attempts, which will produce empathy for patients and affect their self-values. At the same time, they need support from colleagues and nursing managers. Therefore, general hospitals should pay attention to the psychological state of ICU nurses, carry out the targeted communication training and mental health support for ICU nurses, and help them gain positive nursing career growth and values.

BACKGROUND:Hydrogels have become a research hotspot due to their unique advantages in the biomedical field due to their superior mechanical and biological properties.At present,related research involves tissue engineering,wound dressing and so on. OBJECTIVE:To review the advantages and properties of hydrogels and the research progress of their application in the repair of oral and maxillofacial defects,discuss the current limitations and challenges of hydrogels in application and promotion,and provide new ideas for future research directions. METHODS:Relevant literature was searched in PubMed,CNKI,and WanFang database by computer.The search terms were"hydrogel,oral and maxillofacial defects,mechanical properties,tissue engineering,wound dressing"in Chinese and"hydrogel,oral and maxillofacial defects,mechanical properties,guided tissue regeneration,wound dressing"in English.Preliminary screening was carried out by reading titles and abstracts,and articles not related to the topic of the article were excluded.According to the inclusion and exclusion criteria,108 articles were finally included for the result analysis. RESULTS AND CONCLUSION:(1)The hydrogel has good biological activity,mechanical controllability,and stimulation response.(2)Polymer,metal,and ceramic hydrogel composites have appropriate mechanical properties,biodegradability,and controlled release rate,which are suitable for maxillofacial bone tissue engineering.(3)Fibrin-based hydrogel could fill the hollow nerve conduit through the nerve defect area and promote the regeneration and growth of axons to restore the function of maxillofacial nerve.(4)Controlling the interaction between nanomaterials and hydrogels can improve the formation of muscle fiber oriented structure to promote maxillofacial muscle tissue regeneration.(5)Polysaccharide hydrogel has gradually become the first choice for repairing irregular periodontal defects due to its ability to control drug delivery,carry bioactive molecules,and combine with other materials to produce the best scaffold matching the extracellular matrix.(6)Calcium phosphate or calcium carbonate-based hydrogels can be used to fill irregular or fine tissue defects and remineralize hard tissues.The self-assembled hydrogels are simple to prepare and have good biological activity.(7)Salivary gland-derived extracellular matrix-like gel is expected to participate in the treatment of many salivary gland diseases.(8)Hydrogels can be used as wound dressings in combination with biological adhesives,acellular biomaterials,antimicrobials,antioxidants,or stem cells to treat various wounds.(9)Fibrin-based hydrogel has the most potential in the repair of oral and maxillofacial defects.It has excellent biocompatibility,flexibility,and plasticity.It can combine with cells,extracellular matrix proteins,and various growth factors,and promote the osteogenic differentiation of mesenchymal stem cells,axon regeneration and growth,angiogenesis,myotube differentiation,salivary gland tissue regeneration,and periodontal tissue regeneration.It has a broad prospect in the repair of oral and maxillofacial defects.However,its therapeutic effect depends on the function of the substance carried.The complex preparation process,its safety and long-term efficacy,and the special anatomical oral and maxillofacial structure is the problem that hinders its promotion,which also provides directions for future research.

Druggability evaluation is one of the core processes in new drug development, yet the inaccuracy and high cost of existing in vitro liver models have been a major technical bottleneck, leading to an increasing demand from the pharmaceutical industry for reliable in vitro liver models to enhance the efficiency of new drug research and development. Traditional animal models and in vitro 2D culture models have their limitations in simulating in vivo physiological and pathological conditions, making it challenging to accurately predict drug efficacy and safety. With the advancement of microfluidic technology, in vitro cell culture, and biosensor technology, liver-on-a-chip (LOC) has garnered increasing attention in the field of new drug development in recent years, and is expected to become a powerful tool for addressing the challenges in druggability evaluation. While introducing the construction technology of LOC, this article mainly summarizes the research and application of existing LOC from the perspectives of disease model construction, drug metabolism research, and drug safety evaluation. Furthermore, it analyzes the role of LOC in druggability evaluation and discusses the current challenges and prospects in this field.

Objective To evaluate the effectiveness of active screening in improving the detection rate of carbape-nem-resistant Enterobacterales(CRE)in the intensive care units(ICUs).Methods From July 2023 to June 2024,active screening of rectal swab CRE was conducted on ICU patients in 10 hospitals.ICU patients who underwent ac-tive screening from July 2023 to June 2024 were selected as the study group,while those who did not undergo active screening from July 2022 to June 2023 were selected as the control group.Difference in CRE detection rates between the two groups of patients was compared.Results A total of 7 803 ICU patients were included in the study group,744 CRE strains were detected,with a detection rate of 9.53％,out of which 304 CRE strains were detected through routine detection(detection rate 3.90％),3 707 patients underwent active screen,440 CRE strains were detected(detection rate 11.87％).7 561 ICU patients were included in the control group,out of which 250 CRE strains were detected through routine detection,with a detection rate of 3.31％.There was a statistically significant difference in the overall detection rate of CRE between two groups of patients(x2=246.18,P＜0.001).In the study group,CRE detection rate of active screening(11.87％)was higher than that of routine detection(3.90％),with statistically significant difference(x2=264.26,P＜0.001).A total of 17 CRE strains were detected from the study group.The proportions of Klebsiella pneumoniae(80.92％vs 73.41％)and Serratia marcescens(2.30％vs0.23％)in the routine detection group were both higher than in the active screening group,while the proportion of Escherichia coli in the routine detection group was lower(8.22％vs 19.55％),all with statistically significant differences(all P＜0.05).Conclusion The prevalence of CRE in ICUs is relatively high,with a wide range of bac-terial species.Active screening can improve the detection rate of CRE.